Signal Hijack (Goldsmiths University)

Research in reverse engineering surveillance systems for experimentation with media broadcast.


Signal Hijack is an experimental project created in July 2008 in London. The project exploits a vulnerability in commercially available analog wireless CCTV systems operating at 2.4Ghz of frequency in the wireless spectrum. Using a powerful customized RF receiver/transmitter one is able to identify and overtake the RF signal of wireless CCTV. Effectively replacing the original signal from the targeted CCTV camera to broadcast anycontent to the receiving monitor of the target.

The project was deployed as a workshop in United Kingdom and Germany between 2007 and 2008 in which participants could locate and affect signals of existing CCTV cameras in different locations.The project was inspired by the project VideoSniffin’ by Graham Harwood and developed as a master thesis at Goldsmiths University in London.

Standard commercial wireless transmitters/receivers present wireless CCTV cameras, baby monitors follow standardized transmission frequency 2.4GhZ with RF output power that doesn’t exceed 10Mw.The CCTV base monitor is analog, un-encrypted and not paired to a specific camera. This exposes it the possibility exploitation of a stronger bogus signal (above 10mW of RF transisstion power) in the same frequency.

Hijack Devices

The device used in Signal Hijack is a modiried RF receiver/transmitter pair that has been altered to have a greater transmission power than regular wireless analog transceivers.The analog signal is broadcast at a frequency of 2.4Ghz of 2W. The transmitter can broadcast in 4 channels and has a audio/video input and output.When taken to the field the devices are powered by a 12v battery.


Signal Hijack has been employed in the format of workshops in which participants can disturb the existing surveillance landscape by using the receiver devices to capture CCTV signals of urban spaces.By walking to different locations with the devices participants first capture and map the landscape of information from CCTV from inside shops, restaurants, bars homes and government traffic control. The captured signals are then saved mapped to locations where the different signals were found.


As a second part of the field study, participants are then encouraged to design and broadcast their own content using the CCTV landscape as a broadcasting station to monitors in security rooms.

The most common practice in the workshop is to ‘re-wire’ the CCTV landscape. Switching the streams between different cameras creating a disruption in perception of reality. Replacing replacing the original CCTV camera image with custom content created.

My Role

Signal Hijack was part of my graduation project at Goldsmiths, I worked across the creative and technical workstreams, having conceived and created the experimental device.

Further Reference

Signal Hijack was featured in NEWSWEEK article Watching the Watchers.